The present invention relates to change of storage device configuration information and particularly to change of storage device configuration information under the environment that the job profile changes with passage of time.
A storage device of the prior art is capable of introducing various internal configurations depending on users' requests. For example, in some cases, two or more physical disks are combined to configure a logical disk having improved reliability and performance without direct use of physical disks within the storage device. This technique is called RAID (Redundant Array of Inexpensive Disks) and the logical disks are called a parity group or a RAID group. In the RAID technique, a plurality of combination patterns of physical disks are used and these patterns are called as the RAID levels. These RAID levels include the RAID level 0 (also called stripe or striping) for dividing data for every constant size and sequentially writing or reading the divided data to or from a plurality of physical disks, the RAID level 1 (also called mirror) for writing or reading the same data to or from both two physical disks and the RAID level 4 and RAID level 5 (these are different in the way of holding the redundant data) or the like for discretely storing the data to a plurality of physical disks except for only one disk and writing the redundant data for recovering the data to the physical disk to which the data is not stored even if the other physical disks generate faults and can no longer be used.
In the storage device introducing the RAID technique, a parity group is configured utilizing the RAID technique and the entire part or a part of the parity group is defined as the logical disk in such a case that the disk in the storage device is used from a client computer. The logical disk is opened for the designated client computer by the number which is designated by the designated port. A combination of the logical disk, identifier and the number to be opened is called a path, and the logical disk of which path has been defined is called a LU (Logical Unit or Logical Disk Unit). Moreover, the identifier defined to each LU is called a LUN (Logical Unit Number) or HLUN (Host Logical Unit Number). A function for limiting the access to each LU from each client computer is called a LUN Security or LUN masking. In the LUN Security, a unique number given to a network adapter of the client computer is used for identifying the client computer.
Meanwhile, a certain storage device has a function in regard to the access performance to the storage device from the client computer or to the resources such as physical disk and logical disk within the storage device. In the technique called PPC (Port Priority Control), priority of a requested process is given to each port of the storage device and the requested process accepted at the port having the higher priority is processed with priority. Moreover, in the technique called cache residency, the entire part or a part of data included in the LU are permanently reserved in the cache memory within the storage device.
There is also a technique which is called a snapshot for copying the data of logical disk within the storage to another logical disk. Moreover, some storage devices have a function not only for copying the logical disk at the designated timing but also for giving inter-relation between the logical disk as the copying source and the logical disk as the copying destination and for automatically realizing the copying operation to the copying destination when the data is written to the logical disk as the copying source.
A reference, Mark Farley, “Building Storage Networks”, network Professional's Library, Osborne has been issued in regard to RAID, LUN masking and snapshot.
On the other hand, in recent years, the SAN (Storage Area Network), in which a plurality of storage devices and a plurality of client computers utilizing such storage devices are connected through a high speed network such as a fiber channel, has been gained much attention. In the SAN environment, one client computer is capable of simultaneously using two or more storage devices and one storage device may be used from two or more client computers. An example of configuration of SAN is illustrated in FIG. 1. In FIG. 1, the storage devices 1005, 1006, 1007, client computers 1002, 1003 utilizing such storage devices and a management computer 1004 used for management of storage devices are all connected through the network 1001. Here, the management computer 1004 is used to define the configuration of storage device and control the access to the storage devices connected to the network 1001. In the SAN environment in FIG. 1, an administrator executes the job on the management computer 1004 in order to change the configuration of the storage devices 1005, 1006 and 1007. When the management computer 1004 allows access in the SAN environment of FIG. 1, the client computer 1002 is capable of using all storage devices 1005, 1006 and 1007. In the same manner, the client computers 1002 and 1003 can use in common the storage device 1005.
As a reference in regard to the SAN explained above, there is the “Data Storage Report 2000”, Nikkei Computopia, additional edition, 2000.
For the configuration change of a storage device such as parity group, LU, PPC, cache residency and LUN Security, a storage management program is used. This storage management program operates in the management computer connected to the SAN and terminal built in the storage device and a administrator is capable of changing configuration of storage device using this storage management program.
A certain storage management software operating in the management computer automatically executes the backup of data at the prejudged time. Moreover, such software uses in some cases the snapshot explained above to conduct such backup operation. The reference “VERITAS NetBackup DataCenter datasheet” (VERITAS Corp.) is prepared as the storage management software which can execute the backup of data at the prejudged time.
In the actual job in the SAN environment, the internal configuration required for each storage device changes from time to time. In this case, when a administrator uses the configuration in the storage device in direct without change, the optimum performance cannot be attained and the resource application efficiency of the storage device will be deteriorated. However, if a administrator executes manual job when the change of configuration of storage device is necessary, such job is considerably complicated.
Meanwhile, in the case of the storage management software for executing the backup of data at the prejudged time from the management computer, the backup operation cannot be realized as scheduled because the network between the storage device and management computer may be cut out and a fault is generated in the management computer for controlling the storage devices. Moreover, when the storage devices are shifted to the other SAN environment, it is very troublesome because it is also required to simultaneously move the storage management software in the management computer and the schedule data of the relevant software.